I count 7 
Oh yes. I've seen that female Wizard art so many times I forgot to count her as net-new (but somehow counted the male Forcemaster).
Based on location within the image, there would appear to be a male "Johktari" Druid and male "Dsjer-Tet" mage (Necromancer?), along with the previously discussed new female "assassin" (?), on the Academy side. But these two new reveals look a little mature for Academy... Could they be Arena mages?
The female Wizard and male Forcemaster have been anticipated for Arena for a very long time. The silver-haired male with glowing eyes is new, though, and isn't obviously giving away his school or mage type. His armour is reminiscent of the dragon-like Arch-mage that has been floating around for over a year. But given the absence of the known Arch-mage art, perhaps this more humanoid male is replacing the dragon in that role (?).
And then there's the new dark elf mage. It isn't clear to me which school or mage type she belongs to. The colour scheme could indicate a Necromancer in training... and she appears to be young enough to be an Academy mage, which draws into question whether the "Johktari" Druid and "Tsjer-Tet" Necromancer belong to Academy, or if they're location within the image is strategically chosen to throw us off. For example, I could imagine the male Druid and male Dsjer-Tet mage belong to Arena (e.g. a future Johktari vs Dsjer-Tet alt-mage expansion), and this dark elf and the human "assassin" being Academy mages.
